1. Field of the Invention
The present invention relates to an exposure apparatus, and more particularly, to a scanning exposure apparatus which performs projection exposure while synchronously scanning a mask and a wafer.
2. Description of the Related Art
As integrated circuit (IC) patterns have become finer and have been made on a larger scale, an exposure apparatus used in a lithography process employs a system which is widely different from a conventional system.
For example, an excimer laser for emitting light having a wavelength shorter than that of an i-line emitted from a conventional mercury vapor lamp is employed as a light source so as to serve the need for fine IC patterns. In addition, a step-and-scan exposure apparatus is employed so as to serve the need for large-scale IC patterns.
The excimer laser is a pulsed light source accompanied by variations in emission intensity at each emission. Therefore, when the excimer laser is employed in the scanning exposure apparatus, it is necessary to control exposure in some way in order to expose a wafer with the desired exposure amount.
Although various methods of controlling exposure have been conventionally proposed, the scanning exposure apparatus uses many parameters for controlling the exposure. Therefore, it is very important to provide an operator with various information regarding exposure before exposing the wafer. In addition, it is also very important to provide the operator with information such as what processes are being performed, and whether or not any problem has occurred.